This exploratory grant, entitled Rhodiola rosea Therapy of Major Depressive Disorder (MDD), is submitted to the NCCAM under PAR-08-135 to perform human safety and efficacy trials of complementary and alternative medicine (CAM) in the domain of biologically-based practices. We will study the antidepressant action of R. rosea in patients with MDD. Depression affects more than a billion people world wide, and is now recognized as one of the most disabling medical conditions. It accounts for more than 11% of the total disease burden worldwide, and can result in devastating consequences and functional impairment exceeded only by that of cancer and cardiovascular disease. It results in substantial social, occupational, and personal disability and in increased medical co-morbidity and death by suicide. It is considered to be a multi-system disorder characterized by neurotransmitter, neuroendocrine, immunologic, and autonomic disturbances. Although the development of antidepressant drug therapy has simplified the treatment of MDD, a substantial segment of the world's population remains untreated for economic, cultural, or personal reasons. As a result, many individuals seek CAM for relief of their symptoms. The identification of effective CAM therapies for MDD is of public health relevance. R. rosea belongs to the family Crassulaceae, and has a long history as a folk remedy for enhancing physical and emotional endurance. Its adaptogen, or preventive, properties have also led to its use in treating cancer, infection, depression, and other nervous system disorders. Several animal and human studies suggest that R. rosea may have antidepressant properties. For specific aim #1, we will ask: Is R. rosea a safe and effective short-term therapy (vs. sertraline and placebo) for patients with MDD?" To answer this question, patients meeting DSM IV criteria for mild to moderate MDD will be enrolled in a 12-week, randomized, double- blind, placebo-controlled, parallel group, dose-escalation study of R. rosea extract 340-1,360 mg daily vs. sertraline 50-200 mg daily. The primary outcome measure will be change over time in the 17-item Hamilton Depression Rating score. We hypothesize that R. rosea will have superior efficacy vs. placebo and comparable efficacy vs. sertraline. For specific aim #2, we will ask: Does R. rosea therapy result in a favorable tolerability and quality of life (QOL) profile vs. sertraline and placebo? To answer this question, we will obtain safety and QOL measures across treatment conditions that include: (i) frequency, duration, and severity of adverse events, (ii) frequency of serious adverse events, (iii) frequency of dosage reduction, (iv) frequency of treatment discontinuation, and (v) QOL and sexual performance measures. We hypothesize that R. rosea will have a superior tolerability profile vs. sertraline, and similar tolerability vs. placebo. We further hypothesize that R. rosea will have superior QOL and sexual performance ratings vs. sertraline and placebo. Results from this study will be used to inform future research hypotheses and to estimate the effect size necessary to power a future, large scale study. PUBLIC HEALTH RELEVANCE: This application comports with the public health intent of PAR-08-135 to perform clinical trials in humans on the safety, efficacy, toxicity, and optimal dosage of biologically-based complementary and alternative medicine (CAM) therapies. It is an exploratory study of a new therapy for Major Depressive Disorder (MDD), a debilitating illness of uncertain cause. This study will use state-of-the-art clinical trial techniques to evaluate the safety, efficacy, and optimal dosage of Rhodiola rosea in patients with mild to moderate MDD. Results from this study will be used to inform future research hypotheses and to estimate the effect size necessary for conducting a future, large scale CAM study.